Exam 9: Antimalarial Drugs Flashcards Preview

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Flashcards in Exam 9: Antimalarial Drugs Deck (37):
1

What is the most effective way to combat malaria?

Prevention
Killing the mosquitos

2

What is the difference between a clinical cure and a radical cure?

Clinical cure- erythrocytic forms of the parasite are eradicated and the patient has no symptoms.
Radical Cure- All forms of the parasite have been eradicated

3

What is the difference between Causal Prophylaxis and Suppressive Agents?

Causal prophylaxis targets the primary (hepatic) form of the parasite (less practical)
Suppressive Agents- Target erythrocytic forms and suppress symptoms

4

What forms do Chloroquine and Hydroxychloroquine act on?

Erythrocytic forms

5

Chloroquine and Hydroxychloroquine mechanism

Affect the pH of the parasite's food vacuoles, interfering with their feeding

6

For what species are Chloroquine and Hydroxychloroquine clinical cures? Radical cures?

Clinical cures for all
Radical cures for P. falciparum and P. malariae (not vivax and ovale)

7

What is a problem with the use of Chloroquine and Hydroxychloroquine?

Resistance, especially with P. falciparum

8

What causes resistance to Chloroquine and Hydroxychloroquine?

A transport pump that removes the drug from the parasite

9

How are Chloroquine and Hydroxychloroquine metabolized?

Liver

10

What are adverse effects of Chloroquine and Hydroxychloroquine?

CNS- dizziness, headache, tinnitus
GI Upset
Retina and corneal toxicity
Immunological problems

11

In whom are Chloroquine and Hydroxychloroquine contraindicated?

Patients with psoriasis or porphyria
Due to immune effects

12

What is a special use of Hydroxychloroquine?

Rheumatoid Arthritis and SLE due to its anti-inflammatory actions at high doses
(potential for serious toxicity at these doses though...)

13

What is the mechanism of Quinine and Quinidine?

Interference with digestion of hemoglobin

14

What is a time when you'd use Quinine or Quinidine?

Chloroquine-resistant P. falciparum

15

How are Quinine and Quinidine taken?

Orally.
Also an IV preparation of Quinidine in the US

16

What are adverse effects of Quinine and Quinidine?

GI irritation
Visual and auditory disturbances
Bradycardia
Teratogenic/abortion
Skeletal muscle relaxation
Cinchonism (headache, nausea, vomiting, dizziness, tinnitus, blurred vision)

17

When might you use Mefloquine?

Chloroquine-resistant P. falciparum

18

When shouldn't you use Mefloquine?

Serious, life threatening infections.
It can only be taken orally.

19

Adverse effects of Mefloquine?

Seizures
Activates latent psychosis
GI and cardiac problems

20

When is Mefloquine contraindicated?

Patients with epilepsy, mental illness, or cardiovascular problems

21

What are two inhibitors of folic acid synthesis that are used to treat Malaria?

Pyrimethamine and Proguanil

22

What is the mechanism of Pyrimethamine and Proguanil?

Inhibition of DHFR

23

When are Pyrimethamine and Proguanil mostly used?

Prophylaxis, especially against Chloroquine-resistant P. falciparum

24

When might you use pyrimethamine plus sulfadoxine combination?

Presumptive treatment (person shows symptoms, but you haven't diagnosed them for sure yet)

25

What is the mechanism of Atovaquone?

Depolarizes the parasite's mitochondria and inhibiting electron transport

26

What is often used in combo with Atovaquone?

Proguanil (DHFR inhibitor)

27

When might you use Atovaquine + Proguanil?

Prophylaxis against Chloroquine-resistant P. falciparum

28

What are two downsides to Atovaquine + Proguanil?

1. Expensive
2. Must be taken daily

29

What is artemisinin?

An isolate of an herbal preparation that is part of Coartem.

30

What is Coartem?

A product that contains an artemisinin derivative and is quickly becoming the primary drug used to treat most forms of malaria including Chloroquine-resistant P. falciparum

31

What are a couple of regular antibiotics that have activity against plasmodium species?

Tetracycline//doxycycline

32

What is Primaquine used for?

Follow up treatment when you think a person may have been infected with P. vivax or ovale

33

What is the advantage of Primaquine? Disadvantage?

Can kill the plasmodium parasites in the liver (eradicate latent phase)
Disadvantage is that it has toxicities (CNS, GI, and can cause hemolytic anemia in patients with G6PD deficiency)

34

Primaquine toxicity

Hemolytic anemia in patients with G6PD deficiency
GI upset
Headaches/dizziness

35

What would you use for an acute, uncomplicated attack of malaria?

Chloroquine
Quinine/Quinidine
Coartem (artemether/lumefantrine)
Mefloquine
Atovaquine + Proguanil
Doxycycline

36

What is used for a radical cure of P. vivax/ovale?

Primaquine

37

What are 5 drugs used for malaria prophylaxis?

Chloroquine (mostly)
Mefloquine (Chloroquine-resistant P. falciparum)
Doxycycline
Atovaquine + Proguanil
Primaquine (follow up therapy to eradicate P. vivix/ovale